By Dr. Kristie

Oh, those painful cold sores! Cold sores - not to be confused with canker sores - are small, fluid-filled blisters that appear on the face, usually around the lips and mouth. They’re caused by a form of Herpes virus called herpes simplex type one. This is distinct from herpes simplex type two virus that causes painful blisters in the genital region. Herpes cold sores are quite common, affecting up to eight out of ten people at some point in their lives. Which raises the question – can you get herpes from kissing someone who has one of these irritating little blisters?

Can You Get Herpes From Kissing?

You can get herpes from kissing, but only if it’s the type one virus that causes cold sores - not the genital herpes type two virus that’s spread through sexual contact. The reality is most people have already been exposed to the herpes simplex type one virus at some point in their life - and are still harboring it. The virus lies dormant in nerve endings – just waiting to be re-activated when immunity weakens.

Most people are initially infected with the herpes simplex type one virus during childhood after using a towel or toothbrush or kissing someone with an active herpes cold sore. It’s a tough virus to avoid since it can be shed even when a person doesn’t have an obvious cold sore blister - so it’s not surprising that most people already harbor the herpes simplex type one virus. If you check for antibodies against the virus, most people have them even if they haven’t had a recent cold sore.

Preventing the Spread of Herpes Cold Sores

Since the herpes simplex type one virus can be shed even before the blisters appear, to prevent the spread of the virus means not sharing utensils, towels, toothbrushes, or kissing anyone when you feel a cold sore coming on. A herpes cold sore is contagious for more than a week before the blister appears. During this time, some people experience tingling or burning as the herpes cold sore is developing. During this time the virus is very contagious, so avoid kissing anyone until the cold sore completely clears. Once the blister heals, the herpes simplex type one virus is no longer contagious, and it’s okay to kiss again.

Even if you do kiss someone during the time you have a cold sore, the object of your affections may not get it. This is because most people’s immune systems do a good job of fighting it off. Conditions that increase the risk of a herpes cold sore include having another medical condition, taking steroid medication, pregnancy, being fatigued or under stress, malnourished, or getting a sunburn.

Can You Get Herpes from Kissing: The Bottom Line?

The type one virus is very contagious, and you can get herpes from kissing someone who has a herpes cold sore, or who is developing one. On the other hand, most people already have the virus living in their nerve endings – just waiting to be activated if their immunity weakens. The best way to avoid cold sores is to eat a healthy diet, get plenty of rest, and don’t get a sunburn.

References:

Merck Manual. Eighteenth edition. 2006.